[glib] GNetworkMonitorBase: don't fail when IPv6 support is unavailable

[Philip Withnall <pwithnall src gnome org>]

commit f5d1ac0d407c064e58b28feb3b9e34b95458fefe
Author: Erik van Pienbroek <epienbro fedoraproject org>
Date:   Thu Jul 17 21:24:28 2014 +0200

    GNetworkMonitorBase: don't fail when IPv6 support is unavailable
    
    https://bugzilla.gnome.org/show_bug.cgi?id=733338

 gio/gnetworkmonitorbase.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
---
diff --git a/gio/gnetworkmonitorbase.c b/gio/gnetworkmonitorbase.c
index d42f6d4ab..dbded39f8 100644
--- a/gio/gnetworkmonitorbase.c
+++ b/gio/gnetworkmonitorbase.c
@@ -101,8 +101,14 @@ g_network_monitor_base_constructed (GObject *object)
       g_object_unref (mask);
 
       mask = g_inet_address_mask_new_from_string ("::/0", NULL);
-      g_network_monitor_base_add_network (monitor, mask);
-      g_object_unref (mask);
+      if (mask)
+        {
+          /* On some environments (for example Windows without IPv6 support
+           * enabled) the string "::/0" can't be processed and causes
+           * g_inet_address_mask_new_from_string to return NULL */
+          g_network_monitor_base_add_network (monitor, mask);
+          g_object_unref (mask);
+        }
     }
 }